1 of the second technological revolution. /kloc-the development of science in the 0/9th century

19th century is an era when nature is unprecedentedly active and has made some achievements. In physics. Faraday, a British scientist, discovered electromagnetic induction in 1930s. In his experiments, he found that the relative motion between the magnet and the wire is a necessary condition for the magnet to generate electricity, which laid the theoretical foundation of the motor and obtained the key to open the whole treasure house of electric energy for mankind. 1864, Maxwell, a British scientist, published Electromagnetic Theory, which established a systematic electromagnetic theory and further proved the existence of electromagnetic waves. The phenomenon of electromagnetic induction and the discovery of electromagnetic theory have created conditions for us to open up a new era of human production-the electrical era. In addition, the British scientist Joule discovered the phenomenon that electricity generates heat through a conductor, and then invented Joule's law. Later, in 1847, the famous law of conservation and transformation of energy was discovered, which was praised by Engels as1three great discoveries in the 9th century.

Roentgen, a German scientist, discovered the radiation phenomenon in 1895 and unveiled the mystery of X-rays. In biology, German scientists Schleiden and Wang Shi established the cell theory in the late 1930s (65438-2009) on the basis of summarizing previous achievements. From 65438 to 0859, the British biologist Darwin's Origin of Species was officially published, and since then, Darwin's theory of evolution of great significance has been established, which has profoundly inspired human thoughts and souls. In chemistry, Russian scientist Mendeleev discovered the periodic rate of chemical elements in 1868, which laid the foundation of inorganic chemistry. Organic chemistry started in 1870 and took thirty or forty years to establish. /kloc-the establishment of theoretical systems of natural sciences such as physics, chemistry and biology in the 0/9th century prepared conditions for the new revolution required by the development of capitalism. The great development of these natural sciences and a series of breakthrough achievements were quickly and widely used in industrial production, which finally triggered a new and greater technological revolution. Michael faraday (A.D. 179 1 ~ A.D. 1867) was a British physicist and chemist, and a famous self-taught scientist. Born into a poor blacksmith family in Newington, Surrey. Only attended elementary school. 183 1 year, he made a key breakthrough in the force field and changed human civilization forever. 1865438+In May 2005, he returned to the Royal Institute to conduct chemical research under the guidance of David. 1824 1 was elected as a member of the royal society, 1825 was appointed as the laboratory director of the royal society in February, and 1833- 1862 was appointed as the chemistry professor of the royal society. 1846 was awarded the Renford Medal and the Royal Medal.

(1) electrical achievements

1825, David appointed Faraday to carry out optical glass experiments, which lasted for six years and made no significant progress. It was not until David died in 1829 that Faraday stopped this meaningless work and started other meaningful experiments. 183 1 year, he started a series of important experiments and discovered electromagnetic induction. Although he may have foreseen this result in Francesco Zadeh's early work, this discovery can still be called one of Faraday's greatest contributions. His exhibition established the concept of "the change of magnetic field produces electric field" to the world. This relationship is modeled by Faraday's law of electromagnetic induction and becomes one of the four Maxwell equations. When Faraday studied static electricity, he found that the charges on the charged conductor only attached to the surface of the conductor, and the charges on these surfaces had no effect on the interior of the conductor. The reason for this situation is that the charges on the conductor surface are redistributed to a stable state through mutual electrostatic forces, so that the electrostatic forces generated by each charge pair cancel each other out. This effect is called the shadow effect and is applied to Ferrari cages.

(2) Achievements in chemistry

Faraday's earliest chemical achievements came from his time as David's assistant. He spent a lot of time studying chlorine and found two kinds of chlorine carbides. Faraday was also the first scholar to observe gas diffusion through experiments (though it was very rough). This phenomenon was first published by john dalton, and its importance was revealed by Thomas Graham and Joseph Rothschild. He successfully liquefied all kinds of gases; He studied different steel alloys and made many new glasses for optical experiments. One of the samples later occupied a place in history, because Faraday put the glass into a magnetic field and found that the plane of polarized light was repelled by magnetic deflection. He invented a heating tool, the predecessor of bunsen burner, which was widely used as a source of heat energy in scientific laboratories. Faraday has made great achievements in many chemical fields. He discovered chemicals such as benzene (he called this kind of substance bicarburetofhydrogen), invented oxidation number, and liquefied gases such as chlorine. He discovered the composition of a chlorine hydrate, which was first discovered by David in 18 10. Faraday also discovered the law of electrolysis and popularized many technical terms, such as anode, cathode, electrode and ion, which were mostly invented by William sewell.

Slide 7

James clerk maxwell, English physicist and mathematician. In the history of science, it is said that Newton unified the motion law of heaven and earth, which was the first big synthesis, and Maxwell unified electricity and light, which was the second big synthesis, so it should be as famous as Newton. On Electricity and Magnetism, published in 1873, is also considered as the most important physics classic after Newton's Mathematical Principles of Natural Philosophy. Without electromagnetism, there would be no modern electrician technology and no modern civilization.

James clerk maxwell's main achievements

(1) general theory of electromagnetism

After eight years of hard work, Maxwell's monograph on electromagnetism was finally published in 1873, and the book was named "General Theory of Electromagnetism". In the general theory of electromagnetism, Maxwell applied Lagrange equation more thoroughly than before and expanded the formal system of dynamics. Around this period, mathematicians in Britain and continental Europe generally tend to use analytical dynamics more widely in physical problems, and Maxwell's method coincides with that of mathematicians. Moreover, his methods and opinions are novel and attract many people. By applying this popular research trend to electromagnetism, he made fashion his unique achievement. Maxwell used a very new way to demonstrate the symmetry and vector structure of terms, and expressed the Lagrange function of electromagnetic system in the most common form. Maxwell's application of Lagrange method is the first attempt, because it is almost a new method of physics theory. It was many years before other physicists completely used this method to study electromagnetic fields.

(2) the force line of physics

1862, Maxwell completed his thesis "On the Lines of Physical Force". Maxwell's theory of physical magnetic field lines extends the hypothesis of rotation in magnetic field from ordinary matter to ether. He considered the arrangement of vortices in the depth of incompressible fluid. Under normal circumstances, the pressure in all directions is the same, but the centrifugal force generated by rotation makes each vortex shrink longitudinally and produces meridional pressure, which just simulates the stress distribution mentioned in Faraday's force line theory. Because the angular velocity of each vortex is proportional to the local magnetic field strength, Maxwell obtained the same formulas about the force between magnets, constant current and diamagnetism as the existing theory. According to the observation experiment of fluid, Maxwell thinks that each vortex can rotate freely in the same direction because there is a layer of tiny particles between each vortex and its adjacent vortex, which are exactly the same as electricity.

(3) electromagnetic field dynamics theory

1865 published the fourth paper "electromagnetic field dynamics theory", which provided a new theoretical framework for solving pure phenomenological problems with the speed of light. Based on experiments and several general dynamics principles, it is proved that the propagation of electromagnetic waves in space will occur without any special assumptions about molecular vortex or the force between charged particles. In this paper, Maxwell perfected his equation. He adopted the mathematical method founded by Lagrange and Hamilton, and directly deduced the wave equation of electric field and magnetic field from the equation. The propagation speed of wave is the reciprocal of the geometric average of dielectric coefficient and permeability coefficient, which is exactly equal to the speed of light. This result is completely consistent with Maxwell's calculation four years ago. At this point, the existence of electromagnetic waves is certain. From this, Maxwell boldly concluded that light is also an electromagnetic wave. Faraday's hazy conjecture about the electromagnetic theory of light has become a scientific inference after Maxwell's careful calculation. From then on, the names of Faraday and Maxwell, just like the names of Newton and Galileo, are linked together and shine forever in the field of physics. Maxwell once talked about his paper in a letter. He said: "I am completing an electromagnetic theory that contains light. Before I decided that the opposite theory came into being, I thought it was a powerful weapon. " Starting from 1865, Maxwell resigned as the chairman of the Royal Academy of Sciences and began to concentrate on scientific research, systematically summarize the research results and write a monograph on electromagnetism.

(4) Quaternary equation

Many years before Maxwell, people have conducted extensive research on the two fields of electricity and magnetism, and people all know that they are closely related. Various electromagnetic laws applicable to specific occasions have been discovered, but there was no complete and unified theory before Maxwell. Maxwell can accurately describe the characteristics of electromagnetic field and its interaction (but it is very complicated) by listing short four-element equations. In this way, he summed up the chaotic phenomenon into a unified and complete theory. Maxwell equation has been widely used in theory and applied science for a century.

(5) astronomy and thermodynamics

Although Maxwell is famous mainly for his great contributions to electromagnetism and optics, he also made important contributions to many other disciplines, including astronomy and thermodynamics. One of his special interests is gas kinematics. Maxwell realized that not all gas molecules move at the same speed. Some molecules move very slowly, some molecules move very fast, and some molecules move very fast. Maxwell derived a formula to find the percentage of molecules in a known gas moving at a certain speed. This formula is called Maxwell distribution, which is one of the most widely used scientific formulas and plays an important role in many branches of physics.

(6) establish Cavendish laboratory

Another important work of Maxwell was to establish the first physics laboratory of Cambridge University-the famous Cavendish laboratory. This laboratory has had an extremely important influence on the development of experimental physics, and many famous scientists have worked in this laboratory. Cavendish laboratory is even known as "the cradle of Nobel Prize winners in physics". As the first director of the laboratory, Maxwell elaborated the future teaching policy and research spirit of the laboratory in his inaugural speech of 187 1, which was an important speech in the history of science. Maxwell's work route is theoretical physics, but he clearly knows that the era of experimental dominance is not over yet. He criticized the traditional British "chalk" physics at that time and called for strengthening the research of experimental physics and its role in university education, which laid the spirit of experimental science for later generations.

James Prescott Joule (JamesPrescottJoule；; 1818 65438+February 24th-1889 65438+1October1), a British physicist, was born in salford, a suburb of Manchester. Because of his contributions to heat, thermodynamics and electricity, the Royal Society awarded him the highest honor-the Kopre Medal. In order to commemorate him, later generations referred to the unit of energy or work as "Joule" for short, and marked heat with the initials "J" of Joule's surname.

James Prescott Joule's main achievements

Determination of mechanical equivalent of (1) heat

Joule's main contribution is that he studied and measured the equivalent relationship between heat and mechanical work. The first paper on the research work in this field, On the Thermal Effect of Electromagnetic and the Work Value of Heat, was published in 1843, Volume 23, Series 3, British Journal of Philosophy. Since then, he has experimented with different materials and constantly improved the experimental design. It is found that although the methods, equipment and materials used are different, the results are not far apart. And with the improvement of experimental accuracy, it tends to a certain value. Finally, he wrote a paper on the experimental results for many years and published it in the Journal of Philosophy of the Royal Society (Volume 1850). In the paper, he wrote: First, whether it is solid or liquid, the heat generated by friction is always proportional to the amount of force consumed. Second, for 1 pound of water (measured in vacuum, the temperature is between 50 and 60 degrees Fahrenheit), to generate heat that increases 1 degree Fahrenheit, it takes 772 pounds of mechanical work to decrease 1 foot. He has been improved to 1878, and the measurement results are reported. His research work for nearly 40 years has provided unquestionable evidence for the mutual transformation and conservation of thermal motion and other motions, so Joule became one of the discoverers of the law of conservation of energy.

(2) The discovery of Joule's law

1840 65438+in February, he read a paper on heat generation by current in the Royal Society of England, and put forward the law of heat generation by current passing through a conductor; Not long after, Lengci discovered the same law independently, so he called it Joule-Lenz Law.

(3) Achievements in thermodynamics:

1852, Joule and W. Tang Musun (that is, Kelvin) discovered the phenomenon that the temperature drops when the gas expands freely, which is called Joule-Thomson effect. This effect is widely used in low temperature and gas liquefaction. He has done a lot of valuable work for the development of steam engines.

William Conrad Roentgen (German: William Conrad R&; OumlNtgen,1845 March 27th-1923 February 10), a German physicist, 1895 1.5, discovered X-rays. 190 1 won the first nobel prize in physics. This discovery announced the arrival of the era of modern physics and brought about a medical revolution.

(1) wilhelm konrad rontgen's contribution

Roentgen has done experimental research in many fields of physics all his life, such as magnetic effect of dielectric moving in charged capacitor, specific heat capacity of gas, thermal conductivity of crystal, pyroelectric and piezoelectric phenomena, rotation of polarization plane of light in gas, photoelectric relationship, elasticity of matter, capillary phenomenon and so on. 1895 65438+1On October 5th, Roentgen discovered X-rays. His discovery won him great honor. 190 1 won the first nobel prize in physics. This discovery announced the arrival of the era of modern physics and brought about a medical revolution.

(2) cell theory

Cell theory was put forward by German botanist Schleiden and zoologist Wang Shiyu from 1838 to 1839, and was not perfected until 1858. This is a theory about biological composition. The cell theory demonstrates the structural unity and evolutionary homology of the whole biological world. The establishment of this theory has greatly promoted the development of biology and provided an important natural science foundation for dialectical materialism. Engels, the revolutionary mentor, once praised the cell theory, the law of energy conservation and transformation, and Darwin's theory of natural selection as one of the most important natural scientific discoveries in the19th century.

/kloc-Dmitri mendeleev, a Russian chemist in the 10th and 9th centuries, discovered the periodic law of elements and published the world's first periodic table. 1907 On February 2nd, this world-renowned Russian chemist died of myocardial infarction, only six days before his 73rd birthday. His representative work, Principles of Chemistry, was born in the periodic law of elements. It was recognized as a standard work by international academic circles at the end of 19 and the beginning of the 20th century. It was published in eight editions and influenced chemists from generation to generation.

(1) Mendeleev's main contribution

Mendeleev's greatest contribution to the development of chemistry lies in his discovery of the periodic law of chemical elements. On the basis of criticizing and inheriting the work of predecessors, he revised, analyzed and summarized a large number of experimental facts, and summed up such a law: the properties of elements (and their simple substances and compounds) change periodically with the increase of atomic weight (now called relative atomic mass according to national standards), that is, the periodic law of elements. He compiled the first periodic table of elements according to the periodic law of elements, and listed all the 63 elements that had been discovered in the table, which initially completed the task of systematizing elements. He also left a vacancy in the table, predicted the properties of unknown elements such as boron, aluminum and silicon (Mendeleev called them boron-like, aluminum-like and silicon-like, that is, scandium, gallium and germanium later discovered), and pointed out that the atomic weights of some elements determined at that time were wrong. Moreover, he did not mechanically arrange the atomic weight values in the periodic table. Years later, all his predictions were confirmed. The success of Mendeleev's work caused a shock in the scientific community. In order to commemorate his achievements, people call the periodic law and periodic table of elements Mendeleev's periodic law and periodic table of elements.